Gear driving means for centrifugal machines



Nov. 28, 1944.

GEAR

c. A. OLCOTT DRIVING MEANS FOR CENTRI FUGAL MACHINES Filed Dec. 5, 1943 lNl/ENTOP 1 CHARLES/4. OLCOTT ATTORNEY chine. i i InPatent 2,314,286,issued March 16,1943 t Charles A. Olcott; there "isqclisclosed a gear drive arrangement for driving each of a plurality of centrifugal machines positioned in a group from Patented Nov. 28,1944

Fort CENTRMIFUGQL" l A wh s. (01. legas) invention relates to centrifugal machines for separating solid materials fromcontaining liquids and more specifically todriving and con It is an object of this invention to provide novel jgear driving means for a centrifugal maa main drive shaft. The gear drive arrangement has different gear ratios for "the starting and full speedoperationfiof *thema'chine and control means is provided which automatically *establishes the proper; gear ratio'fo r operation of the 1 centrifugal machine atthe desired time. A cenw trifugal governor is provided and arranged so that it prevents the operation of the machine at a; speed in excess-Ora predetermined maximum. In the patentedarrangement, the axis of the main driveshaftis in the same plane as the axis of each of the shafts driving the spindles of the;centrifugalfmachinesu: The presentinvention, in one ofits more important aspects, relates to driving and controlling means for a 'centrifugal machine arrangement wherein the maindriveshaft isnot inthe same plane asthe axis i It is another'object "of-the present invention to providea centrifugal machine gear drive arj rangement between twdshafts whose axes are not in the same plane.

In a specific embodiment of the invention,

there is providedfby wayiof example for illusjtrative purposes,;*atWo'-speed gear driveufor the operation of a 'plurality of centrifugal machines in from a common drive shaft, the axis of 3 this i drive shaft being in a planenwhich is parallel to the planeicontainirig the axis of the shaft (called hereinafter itheflauxiliary drive shaft) used to drive the "spindle of at least one of the centrifugal machines;

main driveshaftandthe two shafts 'oross each other (Without; of course, touching one another). Two sets of two gears each areutilized 1 and these four gears are '50 mounted that they arrangement for assembly and maintenance; The auxiliary shaft projects through the gear casing and shas attached thereto a centrifugal governorxto prevent the speed exceeding a pre- 26, the lengthsofthe link 28 and the slot therein 50 being such that either pair of'cooperating clutch 1 form roughly a rectanglegmaking a convenient 7 GEAR DRWING-MEANS 1 liarlesAQWest Milford, 1 Application December s, 1943, Serial No.- 512,683

determined maximum." Thefactthat thevgove i ernor is located outside the gear assures-r easy adjustment and' -repair of this member 1 The invention will be more readily understood ing to i connect the" centrifugal machine -x to the main driving shaft for: the battery of'imachinesb.

Referring more specifically t to (the sdrawing-i there is shown; by way of example aforilillustraa 1 tive purposes, 'a two' speed gear :drive for a 10611-1 c i trifug'al machine, theis gear 1drive beingmcon structed in accordance'uwit-h the inventions This centrifugal machine; 1 which :h'asca rotating -basket 10, oan be, for exampleLone 'of 3a battery of such machines drivemfrcmamain drive shaft:

ll which is operated bymeansKnQtmshbWm;

such as, "-for exampleL a"synchronous electricl mo tor or a'hydraulic mot'o'n To driveeach-basketm l0 from the main drive shaft N there visnpro-r vided gearing. means comprising 11a :gearcasingw or housing l2 havin openings in whichhare fitted roller bearingstwl3 and M. Mountedfin these roller-bearings and extending .to opposite sides thereof are sleeves -l5 jand l6, carryingbearings l1,-l8, 18A. and 19", in which thejsh'aft a i II is rotatablvmountedfl Keyecb to th'e' sl'eeve l5 at opposite ends thereof are a clutch member H 20 and agear 2l, whilekeyed to thesleeve" at? 'opposite ends thereof areanclutch member 22 and a gear 23, the gear 23 havin'g a smaller nume ber of teeth than the gear 2|. Cooperatingwwithm the clutch members '20" and 22 hare clutch mem bers 24 and 25', respectively; whichiare keyed-rzto rotate with the main drive shaftvll and-Fare movable longitudinally thereof," being operated" .i

by levers 2'6 and 2T,='respectively,to engage and disengage their cooperatingclutchmembers 20'} and 22, respectivelyi n l n l The 1evers 26 and "21a pivotallymounted on the -gear casing l2-and areconnected'by a link' i 28 which has a pivotal connection with the-lever 2] and apin andslot connection-withthe lever members may be engaged and both maybe disengaged but both cannot be engaged at the same time. Tooperatethe levers 26 and j21"there-are provided cylinders 29' and 30T'mounted in exten sions of the wallsb'f the gear casing 11 and haw mounted in the branch pipes and are operated by solenoids 4|] and 4|, respectively, to positions for supplying pressure to the cylinders and,

upon the solenids being de-energized, are returned by the springs 42 and 43, respectively, to

positions for venting air from the" cylinders. 1

necessary to rotate the basket ID at its maximum speed. When the speed of the shaft 46 becomes excessive, the centrifugal action of the Weights 53 overcomes the action .of the spring 59, causing the spring to be compressed and the shaft 51 lowered to separate the clutch members 49 and 58.

Fixed to the clutch member 58 are pins 6|l which slidably engage in openings in a flange 6| fixed on the shaft 62 which drives the basket H]. A brake drum 63 is'secured to the shaft 62 ,and acting thereon is a brake shoe 64 operated by the piston of a brake cylinder 65. Pressure j for operating the brake is supplied from the pipe line through the branch pipe 66 and is con- .trolled by a valve 61 operated by a solenoid In the drawing, valve 39 is shown in the position in which air pressure from the pipe 35 is supplied to the cylinder 30 through the" middle port in the valve 39 and pipe 31 while va1ve38 is shown in the position to vent air from the cylinder 29 'througlrthe pipe 36 and the escape port shownat the left of the valve casing. I

The gears 2| and 23 mesh with other gears 44 and 45, respectively, fixed on a tubular shaft 46. The axis of the shaft 46 isnot in the same plane with th axis of the-main drive shaft H and the two shafts cross one another, the shaft 46 preferably projecting through the top of the gear casing I2. The gears 2|, 23,44, and can be of any form. suitable for drivingone shaft from a second shaft whose axis is not in the same'plane as the axis of the first shaft. By way of example gears known asfhypoid gears can be used. Hypoidgears per se are wellknown and need no further description at this point as their construction i described in any standard gear textbook; As an example,'reference is made to the text entitled Standard gear book (1935) by Reginald Trautschold,,pages 143 and 144. The use'offgears of! this type makes it possible to have the shafts '46 and II cross one another. It will be noted from the drawing that gears 2|, 23, 44-and 45 form roughly a rectangle, a construction which adds to ease of assembly and maintenance.

The shaft-46 is j'ournalled in ball-bearings 41 and 43fixedin innerand outer walls, respectively, of the casing l2. The shaft 46 has fixed atits lowerend a'fiange or clutch-member 49,

the lower face of: which is provided with a friction surface orafriction inserts 50. To the upper end of the shaft 46, outside the casing |2, there.

are pivotally connected the inner ends of links 5|, the outer ends of which are pivotally connected to intermediate points of the lever, arms 52 of a centrifugally .operated'means, one end of each of. the arms 52 having a weight 53 at tached thereto while the other end of each of thearms. is pivotally connected to the shell or outer race 54 of a ball bearing 55, the'inner race 56 .ofwhich is fixed on the end of. a shaft or rod 51. The rod 51 is slidably mounted in the tubular shaft 46- and projectsbelow the lower end of the shaft 46 sufficientlyto have fixed thereon a clutch member 58. Encircling the shaft 51 and confined between the bearing and the end of the shaft .46 is a spring59 of such strength and under such compression as to overcome the downward thrust of the shaft 5'! produced by; the. centrifugal action of the weights53 and hold the clutch member58 in engagement with the clutch:

member 49 tobe driven thereby until the shaft 46 attains a speed slightly in excess of the speed 68. The valve 61 can be of the same type as the valves 38 and39; The solenoid 68, when energized, operates valve 61 to supply pressure to the brake cylinder against the action of a spring 69 and when the solenoid is deenergized the spring returns the valve to a position (the position shown in the drawing) inwhich the pressure is vented from the brake cylinder to the atmos: phere. t

In order to permit easy access to the gears, joints 10, II, 12, and 13 are provided. These joints make it po-ssible for a whole shaft with its bearing and corresponding gear to be pulled out of the gear case without disturbing the other.

The clutch and brake solenoids shown in the drawing can be energized'and de-energized to control the operation of the clutches and brake by means of electrical circuits such as are shown and described-in the above-identified Olcott patent. These circuits comprise no part of the present invention so they are not shown in the drawing.

The operation of the gear mechanism shown in the drawing will now be described. When the basket I0 is at rest, the solenoid 68 is energized causing the brake shoe 64 to be applied to the drum 63 on the shaft 62 by means of air pressure from the pipe 35 applied through the middle port Of the valve 61 (the right hand port be-. ing closed) to the pipe 66 and the cylinder 65. To start rotation of the basket In, the solenoid 68 is de-energized permitting the air brake valve 61 to be operated to vent pressure from the brake cylinder by way of the right hand port of the valve 61 and release the brake. The solenoid 4| is energized to the position shown in the drawing, operating .valve 39 to supply pressure to cylinder 30 by way of the middle port of the valve 39, operating lever 21 against the action of spring 34 to engage the clutch members 25 and 22, causing gear 23 to be drivenby shaft II and operating through gear 45, sleeve 46, clutch members 49 and 58 and shaft 62 to start rotation of the basket ll] of the centrifugal machine.

The ratio of gears 23 and 45 is such that they will drive the basket at substantially half-speed and by proper timing means such as is shown and described in the above-mentioned Olcott patent the rotation of the basket is continued at that speed until the point in the operating cycle for full speed drive is reached. At this point the circuit of the solenoid 4| is interrupted to permit valve 39 to be operated by its spring 43 to the position for venting pressure from the cylinder 30 through the opened right hand port of the valve 39 to allow spring 34 to theopened middle port of the valve 38 for the 2,363,618 thus to supply pressureto cylinder 29 through operation of lever 26and theengaging of the clutch members 24 and 20. The engaging of these twoclutch members causes the gear 2| to be driven by the shaft H and through gear 44, shaft46, clutchinembers 49 and 58 and shaft 52 to drive the basket at fullspeed. The basket is drivenatthis speed forapredetermined period 1 of time. At the expiration of this periodisole noid 40 is de-energized permitting the Valve 38 to be operated to ventpressure from the cylinder 29 through the left hand port of the valve .38 and the lever 26to be operated by spring 33 to separate the clutch members 24 and 20 so that the basket I is no longer driven at full speed from the shaft Solenoid 4| is then energized machine from full to half-speed. The various centrifugal means 53 insure the speed of all bask: ets being kept below an excessiverate at this causing the operation of lever2l to engage clutch members and 22.

As the basket I0 is still rotating under its momentum atsubstantially full speed and as the clutch members 25 and 22 and gears 23 and 45 would drive the basket Ill at only half speed, the

basket Ill tends to speed upthe shaft II when the clutch members 25 and 22 are engaged and the inertia of the shaft I land the other baskets connected thereto exert a braking action on the basket H) which is connected to the shaft through the clutch members 22 and 25. Should it happen that a number of baskets are simultaneous- 1y changed from the condition the shaft through their gears 2| and 44 to that of being connected to the shaft through th'eirgears 45 and 23, their momentum might be sufficient to raise excessively and almost instantly the speed of shaft II and of any baskets driven therefromthrough their gears 2| and 44. The increase in the speed ofthe basket excessively above its normal full speed causes the centrifugal action of the weight members 53 to overcome the resistance of spring 54 and lower. shaft 51 to separate the clutch members 49 and 58 H and disconnect the basket I0 from the drive shaft ll, thus preventing the basket Illfrom being rotated at a dangerous rate. Rotation of the shaft 46 at an excessive speed preferably causes a control switch (not shown but which may be part of the controlling apparatus shown in the Olcott patent) to be opened and interrupt the circuit of the solenoid controlling the operation of the clutch operating lever and maintain the of being driven by slowed to aid in drivingthe other machine and toreduce to some extent the power consumption of the driving motor during the slowing of the the weights 53 andtheir associated mechanisms to be located outside the casing, thus making acoessthereto simple for. adjustment and repair,

and also makes itunnecessar'y to line up the vertical axes of all the ibaskets H] in a single plane. By means of the joints Ill to 13, inclusive,

and the rectangular arrangement of the gears, a

gear can often be changed without tearing down the whole drive mechanisms, Various other advantages of the arrangement in accordance with the invention will readily occur to the workers in the art.

What is claimed is:

1. In a centrifugal machine, a, horizontal drive shaft, a vertical which is in a vertical plane displaced from the Vertical plane containing the axis of said drive mechanism constructed and arranged to drive the machinefrom said horizon- 3 shaft, 2. driving tal shaft at both a highspeed and a low speed,

said mechanism including two sleeves surrounding the main shaft, two hypoid gears of different sizes respectively mounted on said sleeves, a tubular vertical shaft having the same axis as said machine and crossing said main axis, two hypoid circuit open as long as the speed of the shaft 3 remains in excess of the predetermined limit.

In the usual operation the speedof shaft is not raised sufficiently to cause operation of the centrifugal means for any of the baskets connected to the shaft basket whose connectionto the shaft has been changed is graduallyreduced to half speed by the time the circuit of solenoid 4| is interrupted,

permitting the clutch members 25 and 22 to be separated, and the solenoid 58 is energized, causing the brake shoe 54 to be applied to the drum 63 to stop operation of the basket I0 and bring it to its initial position. l

I and the speed of the l The arrangement of gear driveandthecontrol means therefor provides for building up the speed of the basket from rest to half-speed by means of the lower gear ratio provided, .thus greatly lessening the load thrown on the driving motor at the start of each machine and greatly reducing the wear and maintenance onthe clutches and gearing. It also permits maximum acceleration of the basket to half-speed and the building up of the speed of the basket from halfgears of different sizes mounted on said tubular shaft and being constantly in mesh res ectively with the gears on said sleeves, clutch means for connecting said tubular shaft to the shaft of said machine, and clutches associated with said sleeves for selectively causing said sleeves to rotate with said main shaft, a housing for said,

sleeves; clutches,,gears and at least a portion of each of said shafts, and centrifugally operated means driven by said tubular shaft and located outside said housing for disconnecting said tubular shaft from said machine when the speed of said tubular shaft exceeds a predetermined limit.

2. The combinationcf elements as in claim 1 in which said centrifugally operated means operates a rod slidably mounted in said tubular shaft for disengaging the clutch means between said tubular shaft and the shaft of said machine when thespeed of said tubular shaft exceeds said predetermined limit.

3. The. combination of elements as in claim 1 in which said four hypoid gears are arranged to form roughly a. rectangle and said sleeves and the gears associated therewith are removably supported from different parts of said housing whereby one sleeve and the gear, mounted thereon y can be removed for repairuor replacement without disturbing the other sleeve and the gear mounted thereon.

,4. In an upright centrifugal machine having a speed to full speed atthe usual rate of acce1+ 1 eration; Changingtdthe lower gear ratio in deceleraing themachine causes' the one being perations taking place driven shaft having an axis. 9

mounted on said tubular shaft and constantly meshing .respectively with the gears on said sleeves, means for connecting said tubular shaft to the shaft of said machine and means for se-' lectively causing said sleeves to rotate with said main shaft, and centrifugally operated means driven bysaid tubular shaft and located above said main shaft for disconnecting said tubular shaftfrcm said machine when the speed of said 10 tubular shaft exceeds a predetermined limit.

CHARLES, A. OLCOTT- 

